Bisphosphonates inhibit stromelysin-1 (MMP-3), matrix metalloelastase (MMP-12), collagenase-3 (MMP-13) and enamelysin (MMP-20), but not urokinase-type plasminogen activator, and diminish invasion and migration of human malignant and endothelial cell lines

Biological significance and pathophysiological role of Matrix Metalloproteinases in the Central Nervous System

Matrix Metalloproteinases (MMPs), which are endopeptidase reliant on zinc, are low in embryonic tissues but increases in response to a variety of physiological stimulus and pathological stresses. Neuro-glial cells, endothelial cells, fibroblasts, and leucocytes secrete MMPs, which cleave extracellular matrix proteins in a time-dependent manner. MMPs affect synaptic plasticity and the development of short-term memory by controlling the size, shape, and excitatory synapses' function through the lateral diffusion of receptors. In addition, MMPs influence the Extracellular Matrix proteins in the Peri-Neuronal Net at the Neuro-glial interface, which aids in the establishment of long-term memory. Through modulating neuronal, and glial cells migration, differentiation, Neurogenesis, and survival, MMPs impact brain development in mammals. In adult brains, MMPs play a beneficial role in physiological plasticity, which includes learning, memory consolidation, social interaction, and complex behaviors, by proteolytically altering a wide variety of factors, including growth factors, cytokines, receptors, DNA repair enzymes, and matrix proteins. Additionally, stress, depression, addiction, hepatic encephalopathy, and stroke may all have negative effects on MMPs. In addition to their role in glioblastoma development, MMPs influence neurological diseases such as epilepsy, schizophrenia, autism spectrum disorder, brain damage, pain, neurodegeneration, and Alzheimer's and Parkinson's. To help shed light on the potential of MMPs as a therapeutic target for neurodegenerative diseases, this review summarizes their regulation, mode of action, and participation in brain physiological plasticity and pathological damage. Finally, by employing different MMP-based nanotools and inhibitors, MMPs may also be utilized to map the anatomical and functional connectome of the brain, analyze its secretome, and treat neurodegenerative illnesses.

Sodium alendronate is an effective adjunctive therapy for treating periodontitis in male rats treated with anticancer chemotherapy

OBJECTIVES

To assess sodium alendronate as a local adjunctive therapy for treating experimental periodontitis in male rats treated with chemotherapy.

DESIGN

One-hundred-eighty male rats were randomly divided into two groups (n = 90) based on the systemic treatments: PSS, physiological saline solution; and 5-Fluorouracil, and then, subdivided into three subgroups (n = 30): NT, no treatment; scaling and root planing; and sodium alendronate. Treatments were performed 7 days after induction of experimental periodontitis. Specimens were collected at 14, 22, and 37 days after induction. Alveolar bone level, percentage of bone in the furcation, percentage of non-vital bone in the furcation, histopathologic features, and immunolabeling pattern for tartrate-resistant acid phosphatase (TRAP) and osteocalcin (OCN) were evaluated.

RESULTS

The lowest amount of alveolar bone and highest amount of non-vital bone was found in group 5-Fluorouracil when no treatment was performed. In animals receiving 5-Flurouracil and subjected to periodontal treatment, adjunctive sodium alendronate resulted in higher percentage of bone in the furcation and higher alveolar bone loss, when compared with scaling and root planing alone. Better structural and cellularity patterns were found in the periodontal tissues when sodium alendronate was used, regardless of systemic treatment. Higher TRAP-expression was found when no treatment was performed. Sodium alendronate didn't affect the immunolabeling pattern of osteocalcin in the presence of 5-Fluorouracil.

CONCLUSION

Adjunctive therapy with local sodium alendronate prevented alveolar bone loss and improved the histopathological features of the periodontal tissues following scaling and root planing in male rats with experimental periodontitis receiving anticancer chemotherapy with 5-Fluorouracil.

Degradation and Stabilization of Resin-Dentine Interfaces in Polymeric Dental Adhesives: An Updated Review

Instability of the dentine-resin interface is owed to the partial/incomplete penetration of the resin adhesives in the collagen fibrils. However, interfacial hydrolysis of the resin-matrix hybrid layer complex activates the collagenolytic and esterase enzymes that cause the degradation of the hybrid layer. Adequate hybridization is often prevented due to the water trapped between the interfibrillar spaces of the collagen network. Cyclic fatigue rupture and denaturation of the exposed collagen fibrils have been observed on repeated application of masticatory forces. To prevent interfacial microstructure, various approaches have been explored. Techniques that stabilize the resin–dentine bond have utilized endogenous proteases inhibitors, cross linking agents’ incorporation in the exposed collagen fibrils, an adhesive system free of water, and methods to increase the monomer penetration into the adhesives interface. Therefore, it is important to discover and analyze the causes of interfacial degradation and discover methods to stabilize the hybrid layer to execute new technique and materials. To achieve a predictable and durable adhesive resin, restoration is a solution to the many clinical problems arising due to microleakage, loss of integrity of the restoration, secondary caries, and postoperative sensitivity. To enhance the longevity of the resin-dentine bond strength, several experimental strategies have been carried out to improve the resistance to enzymatic degradation by inhibiting intrinsic collagenolytic activity. In addition, biomimetic remineralization research has advanced considerably to contemporary approaches of both intrafibrillar and extrafibrillar remineralization of dental hard tissues. Thus, in the presence of biomimetic analog complete remineralization of collagen, fibers are identified.

Resveratrol suppresses the growth and metastatic potential of cervical cancer by inhibiting STAT3Tyr705 phosphorylation

Aberrant signal transducer and activator of transcription 3 (STAT3) signaling promotes the initiation and progression of cancer in humans by either inhibiting apoptosis or inducing cell proliferation, angiogenesis, invasion, and metastasis. The role of resveratrol（RES）in inhibiting the STAT3 signaling pathway in vivo, particularly in cervical cancer is still unknown. This study aims to investigate the role of STAT3 and its phosphorylation in RES‐mediated suppression of cervical cancer. The effects of RES on cervical cancer were determined by examining tumor tissues, their histological changes, and the volume and weight of tumor tissues grown from HeLa cells injected in female athymic BALB/C nude mice. The structure and target interaction of RES were virtually screened using the molecular docking program Autodock Vina. The status of phosphorylated STAT3, protein levels of epithelial‐mesenchymal transition molecular markers and extracellular matrix degradation enzymes were determined through Western blot. We demonstrated that RES could suppress the proliferation and metastatic potential of cervical cancer cells by inactivating phosphorylation of STAT3 at Tyr705 but not Ser727. This effect was intensified by inhibition of the STAT3 signal pathway.

The Role of Matrix Metalloproteinases in Periodontal Disease

This review provides a detailed description of matrix metalloproteinases (MMPs), focusing on those that are known to have critical roles in bone and periodontal disease. Periodontal disease is an inflammatory process initiated by anaerobic bacteria, which promote the host immune response in the form of a complex network of molecular pathways involving proinflammatory mediators such as cytokines, growth factors, and MMPs. MMPs are a family of 23 endopeptidases, collectively capable of degrading virtually all extracellular matrix (ECM) components. This study critically discusses the available research concerning the involvement of the MMPs in periodontal disease development and progression and presents possible therapeutic strategies. MMPs participate in morphogenesis, physiological tissue turnover, and pathological tissue destruction. Alterations in the regulation of MMP activity are implicated in the manifestation of oral diseases, and MMPs comprise the most important pathway in tissue destruction associated with periodontal disease. MMPs can be considered a risk factor for periodontal disease, and measurements of MMP levels may be useful markers for early detection of periodontitis and as a tool to assess prognostic follow-ups. Detection and inhibition of MMPs could, therefore, be useful in periodontal disease prevention or be an essential part of periodontal disease therapy, which, considering the huge incidence of the disease, may greatly improve oral health globally.

Inhibition of growth and migration of cholangiocarcinoma cells by pamidronate

Pamidronate has been hypothesized to effectively inhibit cancer cell growth and metastasis in bone tissue. Furthermore, pamidronate (Pami) exerts various direct effects against several cancer cell types, including growth and migration. The present study aimed to determine the underlying mechanism of Pami's effect on the proliferation and migration of cholangiocarcinoma (CCA) cells. KKU-100 cells were used to determine the effects of Pami on cell death and migration. The following were assessed: Sulforhodamine B, colony formation, apoptosis via flow cytometry, reactive oxygen species (ROS) production and caspase-3 activity. In addition, the effects of the test compound on the mevalonate (MVA) signaling pathway were determined via western blotting and reverse transcription-quantitative PCR. Cell migration was observed via wound healing, Matrigel and gelatin zymography. The results indicated that Pami induced CCA cell death and inhibited colony formation in a dose-dependent manner, with IC₅₀ values of 444.67±44.05 µM at 24 h and 147.33±17.01 µM at 48 h. Furthermore, Pami treatment suppressed colony formation at a lower concentration than growth inhibition with IC₅₀ values of 5.36±0.31 µM. The mechanism of growth inhibition was determined to potentially be associated with increased ROS generation and stimulated caspase-3 enzyme activity, leading to the induction of apoptosis. Furthermore, Pami treatment interfered with the MVA signaling pathway by reducing Rac1 protein levels and modulating the gene and protein expression of RhoA. Furthermore, Pami suppressed CCA cell migration by decreasing matrix metalloproteinase (MMP)2 and MMP9 levels. Additionally, Pami treatment activated CCA cell death and inhibited CCA migration at low concentrations. Pami significantly decreased the protein expression levels of Rac1 in the MVA signaling pathway and may therefore be beneficial for developing a novel chemotherapeutic method for CCA.

Matrix Metalloproteinases in Bone Resorption, Remodeling, and Repair

Matrix metalloproteinases (MMPs) are the major protease family responsible for the cleavage of the matrisome (global composition of the extracellular matrix (ECM) proteome) and proteins unrelated to the ECM, generating bioactive molecules. These proteins drive ECM remodeling, in association with tissue-specific and cell-anchored inhibitors (TIMPs and RECK, respectively). In the bone, the ECM mediates cell adhesion, mechanotransduction, nucleation of mineralization, and the immobilization of growth factors to protect them from damage or degradation. Since the first description of an MMP in bone tissue, many other MMPs have been identified, as well as their inhibitors. Numerous functions have been assigned to these proteins, including osteoblast/osteocyte differentiation, bone formation, solubilization of the osteoid during bone resorption, osteoclast recruitment and migration, and as a coupling factor in bone remodeling under physiological conditions. In turn, a number of pathologies, associated with imbalanced bone remodeling, arise mainly from MMP overexpression and abnormalities of the ECM, leading to bone osteolysis or bone formation. In this review, we will discuss the functions of MMPs and their inhibitors in bone cells, during bone remodeling, pathological bone resorption (osteoporosis and bone metastasis), bone repair/regeneration, and emergent roles in bone bioengineering.

[Progress on matrix metalloproteinase inhibitors]

Continuing advances in dentin bonding technology and adhesives revolutionized bonding of resin-based composite restorations. However, hybrid layers created by contemporary dentin adhesives present imperfect durability, and degradation of collagen matrix by endogenous enzymes is a significant factor causing destruction of hybrid layers. Bond durability can be improved by using enzyme inhibitors to prevent collagen degradation and to preserve integrity of collagen matrix. This review summarizes progress on matrix metalloproteinase inhibitors (including chlorhexidine, ethylenediaminetetraacetic acid, quaternary ammonium salt, tetracycline and its derivatives, hydroxamic acid inhibitors, bisphosphonate derivative, and cross-linking agents) and suggests prospects for these compounds.

Effects of Pamidronate on Dental Enamel Formation Assessed by Light Microscopy, Energy-Dispersive X-Ray Analysis, Scanning Electron Microscopy, and Microhardness Testing

The aim of the present work was to investigate birefringence and morphology of the secretory-stage enamel organic extracellular matrix (EOECM), and structural and mechanical properties of mature enamel of upper incisors from adult rats that had been treated with pamidronate disodium (0.5 mg/kg/week for 56 days), using transmitted polarizing and bright-field light microscopies (TPLM and BFLM), energy-dispersive X-ray (EDX) analysis, scanning electron microscopy (SEM) and microhardness testing. BFLM showed no morphological changes of the EOECM in pamidronate and control groups, but TPLM revealed a statistically significant reduction in optical retardation values of birefringence brightness of pamidronate-treated rats when compared with control animals (p0.05). The present study indicates that pamidronate can affect birefringence of the secretory-stage EOECM, which does not seem to be associated with significant changes in morphological and/or mechanical properties of mature enamel.

Zoledronate and ion-releasing resins impair dentin collagen degradation

This study analyzed the amounts of solubilized telopeptides cross-linked carboxyterminal telopeptide of type I collagen (ICTP) and C-terminal crosslinked telopeptide of type I collagen (CTX) derived from matrix-metalloproteinases (MMPs) and cysteine cathepsins (CTPs) subsequent to application of a filler-free (Res.A) or an ion-releasing resin (Res.B) to ethylenediaminetetraacetic acid (EDTA)-demineralized dentin with or without zoledronate-containing primer (Zol-primer) pre-treatment. The chemical modification induced following treatments and artificial saliva (AS) storage was also analyzed through attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Totally EDTA-demineralized specimens were infiltrated with Res.A or Res.B with or without Zol-primer pre-treatment, light-cured, and immersed in AS for up to 4 wk. ICTP release was reduced following infiltration with Res.B and further reduced when Res.B was used with Zol-primer; remarkable phosphate mineral uptake was attained after AS storage. CTX release was increased in Res.A- and Res.B-treated dentin. However, when Zol-primer was used with Res.A, the CTX release fell significantly compared to the other tested resin-infiltration methods. In conclusion, zoledronate offers an additional inhibitory effect to the ion-releasing resins in MMP-mediated collagen degradation. However, Zol-primer induces a modest reduction in CTX release only when used with resin-based systems containing no ion-releasing fillers.

Metastasis review: from bench to bedside

Cancer is the final result of uninhibited cell growth that involves an enormous group of associated diseases. One major aspect of cancer is when cells attack adjacent components of the body and spread to other organs, named metastasis, which is the major cause of cancer-related mortality. In developing this process, metastatic cells must successfully negotiate a series of complex steps, including dissociation, invasion, intravasation, extravasation, and dormancy regulated by various signaling pathways. In this review, we will focus on the recent studies and collect a comprehensive encyclopedia in molecular basis of metastasis, and then we will discuss some new potential therapeutics which target the metastasis pathways. Understanding the new aspects on molecular mechanisms and signaling pathways controlling tumor cell metastasis is critical for the development of therapeutic strategies for cancer patients that would be valuable for researchers in both fields of molecular and clinical oncology.

Bisphosphonamidate clodronate prodrug exhibits selective cytotoxic activity against melanoma cell lines

Bisphosphonates are used clinically to treat disorders of calcium metabolism and malignant bone disease and are known to inhibit cancer cell growth, adhesion, and invasion. However, clinical use of these agents for the treatment of extraskeletal disease is limited because of low cell permeability. We recently described a bisphosphonamidate prodrug strategy for efficient intracellular release of bisphosphonates, including clodronate (CLO), in non-small cell lung cancer cells. To evaluate anticancer activity of this prodrug class across many cancer cell types, the bisphosphonamidate clodronate prodrug (CLO prodrug) was screened against the NCI-60 cell line panel, and was found to exhibit selectivity toward melanoma cell lines. Here, we confirm efficient cellular uptake and intracellular activation of this prodrug class in melanoma cells. We further demonstrate inhibition of melanoma cell proliferation, induction of apoptosis, and an antitumor effect of CLO prodrug in a xenograft model. These data suggest a novel therapeutic application for the CLO prodrug and potential to selectively target melanoma cells.

Salivary proteomics in bisphosphonate-related osteonecrosis of the jaw

OBJECTIVE

The objective of this study was to identify differentially expressed salivary proteins in bisphosphonate-related osteonecrosis of the jaw (BRONJ) patients that could serve as biomarkers for BRONJ diagnosis.

SUBJECTS AND METHODS

Whole saliva obtained from 20 BRONJ patients and 20 controls were pooled within groups. The samples were analyzed using iTRAQ-labeled two-dimensional liquid chromatography-tandem mass spectrometry.

RESULTS

Overall, 1340 proteins were identified. Of these, biomarker candidates were selected based on P-value (<0.001), changes in protein expression (≥1.5-fold increase or decrease), and unique peptides identified (≥2). Three comparisons made between BRONJ and control patients identified 200 proteins to be differentially expressed in BRONJ patients. A majority of these proteins were predicted to have a role in drug metabolism and immunological and dermatological diseases. Of all the differentially expressed proteins, we selected metalloproteinase-9 and desmoplakin for further validation. Immunoassays confirmed increased expression of metalloproteinase-9 in individual saliva (P = 0.048) and serum samples (P = 0.05) of BRONJ patients. Desmoplakin was undetectable in saliva. However, desmoplakin levels tended to be lower in BRONJ serum than controls (P = 0.157).

CONCLUSIONS

Multiple pathological reactions are involved in BRONJ development. One or more proteins identified by this study may prove to be useful biomarkers for BRONJ diagnosis. The role of metalloproteinase-9 and desmoplakin in BRONJ requires further investigation.

Alendronate retards the progression of lumbar intervertebral disc degeneration in ovariectomized rats

OBJECTIVE

Increasing evidence has revealed a positive correlation between postmenopausal osteoporosis and intervertebral disc degeneration, the underlying mechanism of which might be associated with changes in the vertebral bone and endplate. Alendronate (ALN) can increase bone mass and improve the microstructure of osteoporotic vertebrae, which might be helpful in preserving disc morphology and mechanical properties. This study aims to investigate the effects of ALN on lumbar intervertebral disc degeneration related to osteoporosis using an ovariectomized (OVX) rat model.

METHODS

Thirty female Sprague-Dawley rats aged 3 months were randomly divided into three groups (with 10 rats each) as follows: the Sham group underwent sham surgery; the OVX + ALN group had twice-a-week subcutaneous injections of ALN (15 μg/kg) for 6 months. The OVX + V group received an equivalent volume of saline solution as placebo post-OVX. After animals were sacrificed at 6 months post-OVX, the L3-6 spinal segments were harvested. Bone mineral density (BMD), micro-CT analysis and biomechanical testing were performed to evaluate the bone quality and microstructural changes in the lumbar vertebral bodies. Histological analysis with van Gieson stain and the histological score were used to identify the characteristics of the degenerative discs. The disc height and the thickness of the cartilage endplate were measured and compared. Immunohistochemistry and real-time PCR measurements for aggrecan, type I collagen, type II collagen, and matrix metalloprotease (MMP)-1, MMP-3 and MMP-13 expressions on the disc were performed to assess the underlying molecular signaling changes in matrix metabolism during intervertebral disc degeneration.

RESULTS

The OVX + ALN group significantly maintained vertebrae BMD, percent bone volume and biomechanical strength, when compared with the OVX + V group. Histological evaluation suggests that there was no significant difference in disc height between the OVX + ALN and Sham groups, and ALN significantly prevented cartilage endplate thickening and the development of abnormal bony tissues within the cartilage endplate. The histological score in the OVX + ALN group was significantly lower than the OVX + V group, suggesting that ALN treatment was effective in delaying the process of the disc degeneration. The results of molecular analysis revealed a significant increase in aggrecan and type II collagen expressions, but marked reductions in MMP-1, MMP-3 and MMP-13 expressions at both the protein and mRNA levels in the OVX + ALN group.

CONCLUSIONS

ALN can retard the progression of lumbar intervertebral disc degeneration in OVX rats. The underlying mechanisms might be related to preservation of the structural integrity and function of the adjacent structures, including the vertebrae and endplates, which further links with modulations in extracellular matrix metabolism to protect the disc from degeneration. These results suggest that ALN might be a promising drug agent for preventing lumbar intervertebral disc degeneration related to osteoporosis.

Metalloproteases and tendinopathy

Matrix metalloproteinases (MMP) are involved in the development of tendinopathy. These potent enzymes completely degrade all components of the connective tissue, modify the extracellular matrix (ECM), and mediate the development of painful tendinopathy. To control the local activity of activated proteinases, the same cells produce tissue inhibitors of metalloproteinases (TIMP). These latter bind to the enzyme and prevent degradation. The balance between the activities of MMPs and TIMPs regulates tendon remodeling, whereas an imbalance produces a collagen dis-regulation and disturbances in tendons. ADAMs (a disintegrin and metalloproteinase) are cell membrane-linked enzymes with proteolytic and cell signaling functions. ADAMTSs (ADAM with thrombospondin motifs) are secreted into the circulation and constitute a heterogenous family of proteases with both anabolic and catabolic functions. Further studies are needed to better define the mechanism of action, and whether these new strategies are safe and effective in larger models.

Alendronate promotes plasmin-mediated MMP-9 inactivation by exposing cryptic plasmin degradation sites within the MMP-9 catalytic domain

Irreversible MMP-9 inhibition is considered a significant therapeutic goal in inflammatory, vascular and tumour pathology. We report that divalent cation chelators Alendronate and EDTA not only directly inhibited MMP-9 but also promoted irreversible plasmin-mediated MMP-9 inactivation by exposing cryptic plasmin-degradation sites within the MMP-9 catalytic-domain and producing an inhibitory hemopexin-domain fragment. This effect was also observed using MDA-MB-231 breast cancer cells, which activated exogenous plasminogen to degrade endogenous proMMP-9 in the presence of Alendronate or EDTA. Degradation-mediated inactivation of proMMP-9 occurred in the absence of transient activation, attesting to the incapacity of plasmin to directly activate proMMP-9 and direct MMP-9 inhibition by Alendronate and EDTA. Our study provides a novel rational for therapeutic Alendronate use in MMP-9-dependent pathology characterised by plasminogen activation.

Antiangiogenic effects of zoledronate on cancer neovasculature

Angiogenesis, one of the hallmarks of cancer, supplies nutrients to cancerous tissues to facilitate rapid growth. Targeting cancer-associated angiogenesis is an important goal in cancer therapy and there are currently many drugs that affect tumor-associated vasculature. In this article, we will focus on the antiangiogenic effects of zoledronate (ZA), a bisphosphonate drug routinely used in the treatment of cancer-associated bone disease. This article covers the known effects of ZA throughout the clinical process. It also covers the animal models of cancer that have been treated with ZA and evaluated for angiogenes is, concluding with the current clinical data pertaining to angiogenic factors after ZA treatment.

Metalloproteases and rotator cuff disease

The molecular changes occurring in rotator cuff tears are still unknown, but much attention has been paid to better understand the role of matrix metalloproteinases (MMP) in the development of tendinopathy. These are potent enzymes that, once activated, can completely degrade all components of the connective tissue, modify the extracellular matrix (ECM), and mediatethe development of painful tendinopathy and tendon rupture. To control the local activity of activated proteinases, the same cells produce tissue inhibitors of metalloproteinases (TIMP) that bind to the enzymes and prevent degradation. The balance between the activities of MMPs and TIMPs regulates tendon remodeling, whereas an imbalance produces a collagen dis-regulation and disturbances intendons. ADAMs (a disintegrin and metalloproteinase) are cell membrane-linked enzymes with proteolytic and cell signaling functions. ADAMTSs (ADAM with thrombospondin motifs) are secreted into the circulation, and constitute a heterogenous family of proteases with both anabolic and catabolic functions. Biologic modulation of endogenous MMP activity to basal levels may reduce pathologic tissue degradation and favorably influence healing after rotator cuff repair. Further studies are needed to better define the mechanism of action, and whether these new strategies are safe and effective in larger models.

Sensitization of ovarian carcinoma cells with zoledronate restores the cytotoxic capacity of Vγ9Vδ2 T cells impaired by the prostaglandin E2 immunosuppressive factor: implications for immunotherapy

Epithelial ovarian cancer (EOC) usually spreads into the peritoneal cavity, thereby providing an opportunity for intraperitoneal adoptive immunotherapy with Vγ9Vδ2 T lymphocytes, a T cell subpopulation endowed with high lytic properties against tumor cells. However, previous studies have reported that Vγ9Vδ2 T cells fail to expand from peripheral blood mononuclear cells in one-third of patients with cancer. Here, from a cohort of 37 patients with EOC, a multiple correspondence analysis identified three populations, one of which was not suitable for Vγ9Vδ2 T-cell adoptive therapy. Interestingly, the ineligible patients were identified based on the frequency of Vγ9Vδ2 T cells in their peripheral blood and the patients' age. The average time to tumor recurrence was also found to be significantly different between the three populations, suggesting that the innate immune response is involved in EOC prognosis. A dramatic decrease in the lytic properties of Vγ9Vδ2 T cells occurred following incubation with ascitic supernatant and was found to be associated with reduced perforin/granzyme degranulation. Prostaglandin E2, but not IL-6, IL-10, VEGF or TGF-β, showed immunosuppressive effects in Vγ9Vδ2 T cells. Interestingly, our results emphasize that pretreating ovarian tumor cells with zoledronate partially reverses the immunosuppressive effects of ovarian cancer-associated ascites and restores a high level of lytic activity. These data sustain that optimal Vγ9Vδ2 T-cell adoptive immunotherapy previously requires counteracting the tumor immunosuppressive microenvironment. Altogether, our findings provide a rationale for clinically evaluating Vγ9Vδ2 T-cell adoptive immunotherapy with intraperitoneal carcinomatosis presensitization by zoledronate in patients with EOC.

Role of metalloproteinases in rotator cuff tear

The role of matrix metalloproteinases (MMPs) and their inhibitors (TIMPS) in the pathophysiology of rotator cuff tears has not been established yet. Recent advances empathize about the role of MMPs and TIMPS in extracellular matrix (ECM) remodeling and degradation in rotator cuff tears pathogenesis and healing after surgical repair. An increase in MMPs synthesis and the resulting MMPs mediated alterations in the ECM of tendons have been implicated in the etiopathogenesis of tendinopathy, and there is an increase in the expression of MMPs and a decrease in TIMP messenger ribonucleic acid expression in tenocytes from degenerative or ruptured tendons. Importantly, MMPs are amenable to inhibition by cheap, safe, and widely available drugs such as the tetracycline antibiotics and bisphosphonates. A better understanding of relationship and activity of these molecules could provide better strategies to optimize outcomes of rotator cuff therapy.

Role of matrix metalloproteinases and therapeutic benefits of their inhibition in spinal cord injury

This review will focus on matrix metalloproteinases (MMPs) and their inhibitors in the context of spinal cord injury (SCI). MMPs have a specific cellular and temporal pattern of expression in the injured spinal cord. Here we consider their diverse functions in the acutely injured cord and during wound healing. Excessive activity of MMPs, and in particular gelatinase B (MMP-9), in the acutely injured cord contributes to disruption of the blood-spinal cord barrier, and the influx of leukocytes into the injured cord, as well as apoptosis. MMP-9 and MMP-2 regulate inflammation and neuropathic pain after peripheral nerve injury and may contribute to SCI-induced pain. Early pharmacologic inhibition of MMPs or the gelatinases (MMP-2 and MMP-9) results in an improvement in long-term neurological recovery and is associated with reduced glial scarring and neuropathic pain. During wound healing, gelatinase A (MMP-2) plays a critical role in limiting the formation of an inhibitory glial scar, and mice that are genetically deficient in this protease showed impaired recovery. Together, these findings illustrate complex, temporally distinct roles of MMPs in SCIs. As early gelatinase activity is detrimental, there is an emerging interest in developing gelatinase-targeted therapeutics that would be specifically tailored to the acute injured spinal cord. Thus, we focus this review on the development of selective gelatinase inhibitors.

Biphenyl sulfonylamino methyl bisphosphonic acids as inhibitors of matrix metalloproteinases and bone resorption

A number of matrix metalloproteinases (MMPs), proteins important in the balance of bone remodeling, play a critical role both in cancer metastasis and in bone matrix turnover associated with the presence of cancer cells in bone. Here, we report the synthesis and biological evaluation of a new class of MMP inhibitors characterized by a bisphosphonate function as the zinc binding group. Since the bisphosphonate group is also implicated in osteoclast inhibition and provides a preferential affinity to biological apatite, the new molecules can be regarded as bone-seeking medicinal agents. Docking experiments were performed to clarify the mode of binding of bisphosphonate inhibitors in the active site of MMP-2. The most promising of the studied bisphosphonates showed nanomolar inhibition against MMP-2 and resulted in potent inhibition of osteoclastic bone resorption in vitro.

Treatment with Tiludronic Acid Helps Reduce the Development of Experimental Osteoarthritis Lesions in Dogs with Anterior Cruciate Ligament Transection Followed by Reconstructive Surgery: A 1-Year Study with Quantitative Magnetic Resonance Imaging

Objective.

To investigate over a 1-year period in dogs that underwent extracapsular stabilization surgery (ECS) following anterior cruciate ligament (ACL) transection: whether reconstructive surgery could prevent osteoarthritis (OA) progression and whether treatment with the bisphosphonate tiludronic acid (TA) could improve the chronic evolution of OA structural changes.

Methods.

ACL transection was performed on dogs on Day 0 and ECS on Day 28. Dogs were randomly divided into 2 groups: 15 received placebo and 16 were treated with TA (2 mg/kg subcutaneous injection) on Days 14, 28, 56, and 84. Magnetic resonance images were acquired on Days −10, 26, 91, 210, and 357, and cartilage volume was quantified. At sacrifice (Day 364), cartilage from femoral condyles and tibial plateaus was macroscopically and histologically evaluated. Expression levels of MMP-1, -3, -13, ADAMTS-4, -5, BMP-2, FGF-2, IGF-1, TGF-ß1, collagen type II, and aggrecan were determined using real-time RT-PCR.

Results.

The loss of cartilage volume observed after ACL transection stabilized following ECS. Thereafter, a gradual gain occurred, with the cartilage volume loss on the tibial plateaus reduced at Day 91 (p < 0.02) and Day 210 (p < 0.001) in the TA-treated dogs. At sacrifice, TA-treated dogs presented a reduction in the severity of macroscopic (p = 0.03 for plateaus) and histologic (p = 0.07 for plateaus) cartilage lesions, had a better preserved collagen network, and showed decreased MMP-13 (p = 0.04), MMP-1 and MMP-3 levels.

Conclusion.

Our findings indicate that in dogs with ACL transection, ECS greatly prevents development of cartilage volume loss. Treatment with TA provided an additional benefit of reducing the development of OA lesions.

The inhibitory effect of polyvinylphosphonic acid on functional matrix metalloproteinase activities in human demineralized dentin

This study has examined the use of polyvinylphosphonic acid (PVPA) as a potential matrix metalloproteinase (MMP) inhibitor and how brief cross-linking of demineralized dentin matrix that did not affect its mechanical properties enhanced the anti-MMP activity of PVPA. The anti-MMP potential of five PVPA concentrations (100-3000 microgml(-1)) was initially screened using a rhMMP-9 colorimetic assay. Demineralized dentin beams were treated with the same five concentrations of PVPA to collagen and then aged for 30 days in a calcium- and zinc-containing medium. The changes in modulus of elasticity, loss of dry mass and dissolution of collagen peptides were measured via three-point bending, precision weighing and hydroxyproline assay, respectively. All tested PVPA concentrations were highly effective (P<0.05) in inhibiting MMP-9. Ageing in the incubation medium did not significantly alter the modulus of elasticity of the five PVPA treatment groups. Conversely, aged dentin beams from the control group exhibited a significant decline in their modulus of elasticity (P<0.05) over time. Mass loss from the dentin beams and the corresponding increase in hydroxyproline in the medium in the five PVPA treatment groups were significantly lower than for the control (P<0.05). PVPA is a potent inhibitor of endogenous MMP activities in demineralized dentin. It may be used as an alternative to chlorhexidine to prevent collagen degradation within hybrid layers to extend the longevity of resin-dentin bonds.

In vivo effects of zoledronic acid on oral mucosal epithelial cells

OBJECTIVE

Osteonecrosis of the jaw is a serious complication of bisphosphonate treatment for which the pathophysiology is unknown. The purpose of this study was to investigate whether in vivo zoledronic acid (ZA) induces alterations in cell proliferation, apoptosis, and matrix metalloproteinases (MMPs) expression in oral mucosal epithelial cells.

METHODS

One-year-old dogs were either untreated (control group) or given high doses of intravenous ZA (ZA group) for 3 months. The doses of ZA were equivalent to those given to cancer patients, yet were administered two times more frequently (every 2 weeks). Mucosal tissues were assessed immunohistochemically for cell proliferation (proliferating cell nuclear antigen, PCNA), matrix metalloproteinase (MMP) expression, and apoptosis (caspase 3 and TUNEL).

RESULTS

There were no significant differences between the groups with respect to PCNA, MMP-2, MMP-14, and TUNEL positive cells. However, the expression of MMP-9 was significantly higher in the control group than in the ZA group (P < 0.05), whereas the expression of caspase 3 was significantly lower in the control group than in the ZA group (P < 0.05).

CONCLUSION

  These results suggest that high doses of ZA resulted in higher levels of apoptosis and lower levels of MMP-9 in the oral epithelial cells supporting the idea of bisphosphonate treatment affects the oral mucosa.

Birefringence of the secretory-stage enamel organic extracellular matrix from rats submitted to successive injections of bisphosphonates

The aim of the present study was to assess birefringence of the secretory-stage enamel organic extracellular matrix (ECM) and mechanical properties of mature enamel from rats treated with bisphosphonates. Longitudinal sections were obtained from upper incisors of rats that had been submitted to injections of bisodic etidronate (8 mg/Kg/day), sodium alendronate (30 microg/Kg/day), or sodium chloride as control (8 mg/Kg/day) for 42 days. Sections were immersed in 80% glycerin for 30 min and optical retardation of birefringence brightness in the secretory-stage enamel organic ECM was determined in nanometers. Etidronate-treated rats exhibited extensive morphological changes in the secretory-stage enamel organic ECM inclusive nonbirefringent conspicuous incremental lines, but presented optical retardation values similar to those showed by control rats (p > 0.05). Birefringence of secretory enamel organic ECM from etidronate rats presented an irregular aspect. Alendronate-treated rats did not show morphological alterations in the secretory-stage enamel organic ECM, however, they presented significant reduction in optical retardation of birefringence brightness when compared with control and etidronate rats (p < 0.01). Alendronate and etidronate groups exhibited reductions of approximately 6-10% in mature enamel cross-sectional microhardness when compared with control group (p < 0.01). Scanning electron microscopy analysis showed extensive alterations in mature enamel only from etidronate group with absence of enamel rods. The present work shows that bisphosphonates can affect the birefringence of the secretory-stage enamel organic ECM. The results presented here suggest that alterations in the supramolecular organization of the secretory-stage enamel organic ECM are a plausible mechanism by which environmental factors may cause enamel defects.

Metalloproteinases and their inhibitors-diagnostic and therapeutic opportunities in orthopedics

Matrix metalloproteinases (MMPs) and related enzymes (ADAMs, ADAMTS) and their inhibitors control matrix turnover and function. Recent advances in our understanding of musculoskeletal conditions such as tendinopathy, arthritis, Dupuytren's disease, degenerative disc disease, and bone and soft tissue healing suggest that MMPs have prominant roles. Importantly, MMPs are amenable to inhibition by cheap, safe, and widely available drugs such as the tetracycline antibiotics and the bisphosphonates. This indicates that these MMP inhibitors, if proven effective for any novel indication, may be quickly brought into clinical practice.

Inhibition of MMP-3 activity and invasion of the MDA-MB-231 human invasive breast carcinoma cell line by bioflavonoids

AIM

Stromelysin 1 (matrix metalloproteinase 3; MMP-3) is an enzyme known to be involved in tumor invasion and metastasis. In this study, flavonoids from vegetables and fruits, such as quercetin, kaempferol, genistein, genistin, and daidzein, were tested for their ability to modulate the secretion and activity of MMP-3 in the MDA-MB-231 breast cancer cell line. In addition, we investigated the in vitro effects of flavonoids on MDA-MB-231 cell invasion.

METHODS

The toxic concentration range of flavonoids was evaluated using the MTT assay. The ability of MDA-MB-231 cells to invade was evaluated using a modified Boyden chamber system. The activity of MMP-3 was determined by casein zymography. The secretion of MMP-3 was evaluated using Western blotting, casein zymography and confirmed by ELISA.

RESULTS

Some putative flavonoids, ie, quercetin and kaempferol (flavonols), significantly inhibited the in vitro invasion of MDA-MB-231 cells in a concentration-dependent manner, with IC(50) values of 27 and 30 micromol/L, respectively. Quercetin and kaempferol also reduced MMP-3 activity in a dose-dependent manner, with IC(50) values in the range of 30 micromol/L and 45 micromol/L, respectively. None of the flavonoids had a significant effect on the secretion of MMP-3.

CONCLUSION

These data show that the flavonols quercetin and kaempferol have higher anti-invasion potency and higher MMP-3 inhibitory activity than isoflavones genistein, genistin and daidzein. In contrast, neither flavonols nor isoflavones have any effect on MMP-3 secretion.

Biological behaviors and proteomics analysis of hybrid cell line EAhy926 and its parent cell line A549

Background

It is well established that cancer cells can fuse with endothelial cells to form hybrid cells spontaneously, which facilitates cancer cells traversing the endothelial barrier to form metastases. However, up to now, little is known about the biologic characteristics of hybrid cells. Therefore, we investigate the malignant biologic behaviors and proteins expression of the hybrid cell line EAhy926 with its parent cell line A549.

Methods

Cell counting and flow cytometry assay were carried out to assess cell proliferation. The number of cells attached to the extracellular matrix (Matrigel) was measured by MTT assay for the adhesion ability of cells. Transwell chambers were established for detecting the ability of cell migration and invasion. Tumor xenograft test was carried out to observe tumorigenesis of the cell lines. In addition, two-dimensional electrophoresis (2-DE) and mass spectrometry were utilized to identify differentially expressed proteins between in Eahy926 cells and in A549 cells.

Results

The doubling time of EAhy926 cell and A549 cell proliferation was 25.32 h and 27.29 h, respectively (P > 0.1). Comparing the phase distribution of cell cycle of EAhy926 cells with that of A549 cells, the percentage of cells in G0/G1 phase, in S phase and in G2/M phase was (63.7% ± 2.65%) VS (60.0% ± 3.17%), (15.4% ± 1.52%) VS (13.8% ± 1.32%), and (20.9% ± 3.40%) VS (26.3% ± 3.17%), respectively (P > 0.05). For the ability of cell adhesion of EAhy926 cells and A549 cells, the value of OD in Eahy926 cells was significantly higher than that in A549 cells (0.3236 ± 0.0514 VS 0.2434 ± 0.0390, P < 0.004). We also found that the migration ability of Eahy926 cells was stronger than that of A549 cells (28.00 ± 2.65 VS 18.00 ± 1.00, P < 0.01), and that the invasion ability of Eahy926 cells was significantly weak than that of A549 cells (15.33 ± 0.58 VS 26.67 ± 2.52, P < 0.01). In the xenograft tumor model, expansive masses of classic tumor were found in the A549 cells group, while subcutaneous inflammatory focuses were found in the EAhy926 cells group. Besides, twenty-eight proteins were identified differentially expressed between in EAhy926 cells and in A549 cells by proteomics technologies.

Conclusion

As for the biological behaviors, the ability of cell proliferation in Eahy926 cells was similar to that in A549 cells, but the ability in adhesion and migration of Eahy926 cells was higher. In addition, Eahy926 cells had weaker ability in invasion and could not form tumor mass. Furthermore, there were many differently expressed proteins between hybrid cell line Eahy926 cells and A549 cells, which might partly account for some of the differences between their biological behaviors at the molecular level. These results may help to understand the processes of tumor angiogenesis, invasion and metastasis, and to search for screening method for more targets for tumor therapy in future.

Assessment of metalloproteinase inhibitors clodronate and doxycycline in the neutralization of hemorrhage and coagulopathy induced by Bothrops asper snake venom

Snake venom metalloproteinases (SVMPs) play a prominent role in the local and systemic manifestations of viperid snakebite envenomations. Thus, the possibility of using metalloproteinase inhibitors in the treatment of these envenomations is a promising therapeutic alternative. This study assessed the ability of two metalloproteinase inhibitors, the biphosphonate clodronate and the tetracycline doxycycline, to inhibit proteolytic, hemorrhagic, coagulant and defibrinogenating effects of Bothrops asper venom. Both compounds were able to inhibit these activities, at concentrations in the mM range, when incubated with venom prior to testing. However, when inhibition of hemorrhage was assessed in assays involving independent injection of venom and drug, inhibition was poor, even when these compounds were injected immediately after envenomation. These findings support the concept that the effectiveness of compounds, such as clodronate and doxycycline, whose inhibitory action on SVMPs is based on zinc chelation alone, is limited, and stress the view that more specific molecules are required for an effective inhibition of SVMPs in vivo.

Effects of alendronate and pamidronate on cultured rat metatarsal bones: failure to prevent dexamethasone-induced growth retardation

Bisphosphonates are widely used anti-resorptive drugs in the adult population. In children, their use has mainly been limited to patients with osteogenesis imperfecta. However, the powerful effects of bisphosphonates on bone turnover have raised concern about their long-term effects on the growing skeleton. We aimed to study the effects of two commonly used bisphosphonates, alendronate (Aln) and pamidronate (Pam) on normal bone growth as well as their potential to prevent glucocorticoid-induced growth retardation. Effects on bone growth were studied in fetal rat metatarsal bones (day E20) that were cultured for 5-47 days and measured every 2-7 days. Cellular mechanisms were investigated in metatarsal bones and also in the human chondrocytic cell line HCS-2/8. Chondrocyte viability (WST-1), proliferation (BrdU incorporation), differentiation (collagen type X immunohistochemistry) and apoptosis (TUNEL and Cell Death ELISA) were determined. At a clinically relevant concentration of bisphosphonates (1 microM), metatarsal bone growth was stimulated by both Aln (p<0.001 for length and p<0.05 for width) and Pam (p<0.05 for both length and width) from day 19 of culture. The growth-stimulatory effect was associated with increased chondrocyte proliferation (+21% with Aln and +24% with Pam), while cell differentiation and apoptosis were not affected. Despite the finding that both Aln and Pam (1 muM) rescued HCS-2/8 cells from undergoing dexamethasone-induced apoptosis, neither of them was able to prevent dexamethasone-induced growth retardation of fetal rat metatarsal bones. Aln and Pam have the capacity to stimulate the growth of cultured fetal rat metatarsal bones; an effect associated with increased proliferation of growth plate chondrocytes. Our experimental data suggest that bisphosphonates are ineffective in preventing glucocorticoid-induced growth retardation. Nevertheless, based on our in vitro data, both Aln and Pam appear safe to use in growing children, at least with regard to their effects on linear bone growth.

Attenuation of protease activity in chronic wound fluid with bisphosphonate-functionalised hydrogels

Chronic ulcers are an important and costly medical issue, imposing considerable pain, reduced mobility and decreased quality of life. The common pathology in these chronic wounds is excessive proteolytic activity, resulting in degradation of key factors critical to the ulcer's ability to heal. Matrix metalloproteinases (MMPs), a large family of zinc-dependent endopeptidases, have been shown to have increased activity in chronic wound fluid (CWF), with many authors suggesting that they need to be inhibited for the ulcer to heal. The studies we report here show that the excessive MMP activity in CWF can be inhibited with the bisphosphonate alendronate, in the form of a sodium salt, a functionalised analogue, and tethered to a poly(2-hydroxy methacrylate) (PHEMA) hydrogel. Furthermore, these functionalised alendronate hydrogels appear to be biologically inert as assessed in a three-dimensional ex vivo human skin equivalent model. Together, these results highlight the potential use of a tethered MMP inhibitor to inhibit protease activity in wound fluid. This approach may improve wound healing as it still allows MMPs to remain active in the upper cellular layers of the ulcer bed where they perform vital roles in wound healing; thus may offer an attractive new device-orientated wound therapy.

The role of bisphosphonates in the management of patients that have cancer

Bisphosphonates are pharmacologic agents widely used in people for managing pathologic bone resorptive conditions. Based on their physicochemical properties, bisphosphonates concentrate within areas of active bone remodeling and induce osteoclast apoptosis. Appropriate use of bisphosphonates for treating companion animals requires a thorough understanding of how bisphosphonates exert their biologic effects. This review article highlights general properties of bisphosphonates, including their pharmacology, mechanisms of action, adverse side effects, anticancer mechanisms, surrogate markers for assessing response, and potential clinical utility for treating dogs and cats diagnosed with malignant skeletal tumors.

On the horizon: can bisphosphonates prevent bone metastases?

Skeletal complications of bone metastases increase the risk of death and undermine patients' functional independence and quality of life. Although bisphosphonates are integral in the treatment regimen of patients with metastatic bone disease and have demonstrated efficacy in delaying the onset and reducing the incidence of skeletal-related events, there is great interest in developing treatments to prevent metastasis to bone. Emerging evidence indicates that the potential benefits of bisphosphonate therapy extend beyond the treatment of metastatic bone lesions. Data from preclinical studies suggest that bisphosphonates may have antitumour activity and may prevent bone metastasis. The mechanisms of these antitumour effects are currently under investigation and may include induction of apoptosis, inhibition of tumour cell invasion and angiogenesis, and tumour growth reduction. Therefore, patients with early-stage disease may benefit from early bisphosphonate therapy, before bone metastasis develops, and investigations are ongoing to determine the clinical utility of bisphosphonates in this setting.

Alendronate inhibits cell invasion and MMP-2 secretion in human chondrosarcoma cell line

AIM

Chondrosarcoma is a malignant primary bone tumor that responds poorly to both chemotherapy and radiation therapy. The aim of the present study was to investigate the effect of alendronate, a bisphosphonate, on the invasion and migration of human chondrosarcoma cells (JJ012).

METHODS

JJ012 cells were treated with alendronate of various concentrations up to 100 micromol/L for a specified period, and then gelatin zymography and matrigel invasion assay was performed to study the effects of alendronate on matrix metalloproteinase (MMP)-2 activity and the invasion ability of JJ012 cells, respectively.

RESULTS

Our data showed that alendronate exerted a dose- and time-dependent inhibitory effect on the invasion and migration of JJ012 cells. Furthermore, gelatin zymography and RT-PCR showed that alendronate treatment decreased the activity and mRNA levels of MMP-2 in a concentration-dependent manner.

CONCLUSION

Our findings suggest that alendronate may reduce MMP-2 secretion at the transcriptional and translational levels, and inhibit the invasion of chondrosarcoma cell. Therefore, alendronate may be a potential candidate for the systemic therapy of chondrosarcomas, as well as other malignant diseases.

Inhibition of bone healing by pamidronate in calvarial bony defects

OBJECTIVE

Pamidronate has been studied as a therapeutic drug for various osteopenic diseases. However, avascular osteonecrosis in the jawbone has been recently reported in patients receiving pamidronate. The objective of this study was to examine the effect of pamidronate on bone regeneration in a controlled animal model.

MATERIALS AND METHODS

To determine the effect of parmidronate on bone healing in a local bony defect area, a rabbit calvarial bony defect model was used and poly L-lactide-co-glycolide (PLGA) used as a drug carrier material. Four defect groups were made in each rabbit calvaria and the defects were treated as follows: untreated bony defect (group 1), PLGA only (group 2), 2 mg of pamidronate with PLGA (group 3), and 3 mg of pamidronate with PLGA (group 4). Bone healing was evaluated by radiography and histology at 1, 2, 4, 6, and 8 weeks after surgery.

RESULTS

In radiographic analysis, radiopacity was lower in pamidronate groups than non-operated rabbit calvarial bone at all observation points (P < .05). In histological analysis, the initial bone formation at 1 week was not different among groups, but it was much lower in the pamidronate groups than in the control or PLGA group after 2 weeks. Newly formed bone at 1 week underwent avascular necrosis after 2 weeks in both pamidronate groups. Avascular necrosis was not observed until 8 weeks in both topically applied pamidronate groups.

CONCLUSION

Collectively, pamidronate inhibits bone healing in rabbit calvarial bony defect and it may explain the avascular necrosis of the jaws in patients receiving pamidronate.

Matrix metalloproteinases, tissue inhibitor of matrix metalloproteinase-1, and laminin-5 gamma2 chain immunolocalization in gingival tissue of endotoxin-induced periodontitis in rats: effects of low-dose doxycycline and alendronate

BACKGROUND

Matrix metalloproteinases (MMPs) play important roles in tissue destruction mechanisms of periodontitis. MMP-8 and -13 are the major collagenases that act in extracellular matrix degradation in periodontal tissues. MMP-14 is a membrane-type MMP, and laminin (Ln)-5 is a basal membrane component. The aim of the present study was to evaluate the effects of doxycycline and alendronate on gingival tissue expression of MMP-8, -13, and -14; tissue inhibitors of MMP (TIMP)-1; and Ln-5 gamma2 chain in experimental periodontitis induced by Escherichia coli endotoxin (LPS) in rats.

METHODS

Experimental periodontitis was induced by repeated injection of LPS. Forty-four adult male Sprague-Dawley rats were divided into five study groups: saline control, LPS, LPS + doxycycline, LPS + alendronate, and LPS + doxycycline + alendronate. Doxycycline and alendronate were given as a single agent or as combination therapy during the 7 days of the experimental study period. On day 7, the rats were sacrificed, and the gingival tissues were analyzed immunohistochemically for expression of MMP-8, -13, and -14, Ln-5 gamma2 chain, and TIMP-1. Alveolar bone loss was evaluated morphometrically under a stereomicroscope. Data were tested statistically by Kruskal-Wallis and Mann-Whitney tests and Spearman correlation analysis.

RESULTS

Alveolar bone loss was significantly higher in the LPS, doxycycline, alendronate, and combination groups than in the saline control group (all P <0.01). MMP-8 expression was significantly higher in the LPS group than in the saline control group (P = 0.001). Individual administration of doxycycline or alendronate significantly decreased the expression of MMP-8 compared to LPS (P = 0.01). Combined drug administration reduced MMP-14 significantly compared to doxycycline (P = 0.004). No significant differences in Ln-5 gamma2 chain expression were found between the study groups (P >0.05). MMP-14 significantly correlated with the Ln-5 gamma2 chain in the LPS + alendronate group (P = 0.04) and with the amount of alveolar bone loss in the LPS + doxycycline + alendronate group (P = 0.03).

CONCLUSIONS

Our findings suggest that alendronate and/or doxycycline may inhibit MMP-8 expression significantly; particularly, their combined administration may provide beneficial effects in periodontal treatment. Moreover, individual administration of alendronate and doxycycline results in significant increases in TIMP-1 expression in gingiva. However, these effects of combined low-dose doxycycline and alendronate on MMPs and TIMP should be verified by clinical human trials before these agents are used in dental practice.

In vitro inhibition of matrix metalloproteinase activity in tracheal epithelial lining fluid from horses with recurrent airway obstruction

OBJECTIVE

To evaluate inhibitory effects of synthetic matrix metalloproteinase (MMP) inhibitors in vitro on gelatinolytic and collagenolytic activities in tracheal epithelial lining fluid (TELF) of horses with recurrent airway obstruction (RAO).

ANIMALS

10 horses with RAO and 5 healthy control horses.

PROCEDURES

Substrate-based functional assays, collagen I and gelatin degradation, were used to measure endogenous collagenolytic and gelatinolytic activities in TELF. In vitro inhibition of MMP activity in TELF with 2 chemically modified tetracyclines (CMTs; CMT-3 and CMT-8) and 2 bisphosphonates (BPs; zoledronate and pamidronate) was evaluated.

RESULTS

CMT-3, CMT-8, zoledronate, and pamidronate in a dose-dependent manner inhibited TELF type I collagenolytic and gelatinolytic activities, although no complete inhibition of TELF type I collagenolytic and gelatinolytic activities was achieved with the inhibitor concentrations of 25 to 500 microM tested. The CMTs inhibited pathologically induced collagen I degradation more effectively than BPs. Of the tested CMTs, CMT-3 was the most effective inhibitor of gelatinolytic activity, and the efficiency of CMT-3 corresponded with that of the BPs.

CONCLUSIONS AND CLINICAL RELEVANCE

An increase in MMP activity in the equine respiratory tract may potentially be inhibited by administration of CMTs or BPs. Distinct synthetic MMP inhibitors may eventually provide an additional means for pharmacologic treatment by decreasing ongoing active tissue destructive inflammation associated with chronic lung disease. The MMP inhibitors such as CMTs and BPs that are targeted to solely inhibit a pathologic increase in MMP activities provide the advantage of minimal adverse effects that are characteristics of other excessively potent MMP inhibitors.

Contact of high-invasive, but not low-invasive, melanoma cells to native collagen I induces the release of mature cathepsin B

Metastasis of malignant tumor cells involves cell-cell and cell-matrix interactions, which regulate the expression and localization of proteolytic enzymes. In the present study, we investigated the expression and localization of the lysosomal cysteine proteinase cathepsin B and its natural inhibitors cystatin A, B and C in high- (MV3), intermediate- (SKmel28) and low-invasive (SKmel23, WM164) human melanoma cell lines grown on plastic or in contact with monomeric or fibrillar collagen type I. Neither the transcript levels of cathepsin B nor those of the natural inhibitors, cystatin B and C, were altered by the interaction of melanoma cells with collagen type I. However, protein expression and cellular localization of cathepsin B and its inhibitors were markedly affected. In contrast to low-invasive cells, high-invasive cells constitutively released procathepsin B when cultured on plastic. In addition, contact of invasive cells with fibrillar collagen type I resulted in the release of both mature forms of the protease. Perturbation studies using inhibitory antibodies against the beta1 subunit of the integrin receptor indicated a role for the beta1 integrin receptor family in the regulation of cathepsin B release. Cystatin B protein expression was much lower in high-invasive cells in both culture conditions, when compared to low-invasive cells. Cystatin C expression was comparable in all cells, but cell contact to fibrillar collagen type I induced its expression. These results strongly implicate a pivotal role of cell-matrix interactions for the regulation of cathepsin B localization and activity in melanoma cells.